Engineering Commons^™

The Applications Of Additive Manufacturing Technologies In Cyber-Enabled Manufacturing Systems, Sriram Praneeth Isanaka, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The application of networked sensors and control in various areas, such as smart grids and infrastructures, has become a recent trend, called cyber-physical systems. The Cyber Enabled Manufacturing (CEM) environment is to apply these technologies in manufacturing systems to handle a significantly greater magnitude of manufacturing data. Additive manufacturing techniques print or place material layer by layer to form a part, thus have a great potential to help accelerate CEM process by printing or embedding sensors and actuators in the proper locations. This paper summarizes the roles of additive manufacturing technologies to help establish a CEM environment.

Freeze-Form Extrusion Fabrication Of Functionally Graded Material Composites Using Zirconium Carbide And Tungsten, Ang Li, Aaron S. Thornton, Bradley K. Deuser, Jeremy Lee Watts, Ming-Chuan Leu, Greg Hilmas, Robert G. Landers

Materials Science and Engineering Faculty Research & Creative Works

Ultra-high-temperature ceramics are being investigated for future use in aerospace applications due to their superior thermo-mechanical properties, as well as their oxidation resistance, at temperatures above 2000⁰C. However, their brittleness makes them susceptible to thermal shock failure. As graded composites, components fabricated as functionally-graded materials (FGMs) can combine the superior properties of ceramics with the toughness of an underlying refractory metal. This paper discusses the grading of two materials through the use of a Freeze-form Extrusion Fabrication (FEF) system to build FGM parts consisting of zirconium carbide (ZrC) and tungsten (W). Aqueous-based colloidal suspensions of ZrC and W were developed …

Modeling, Analysis And Simulation Of Paste Freezing In Freeze-Form Extrusion Fabrication, Mingyang Li, Robert G. Landers, Ming-Chuan Leu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

During the freeze-form extrusion fabrication process for aqueous-based pastes, the sub-zero temperature environment aids the part in maintaining its shape by freezing the water present in the paste. The paste freezes very quickly when deposited on a substrate in a freezing environment. However, as the part’s height increases, the freezing time increases as the heat conduction rate to the substrate decreases. The freezing time can exceed the time required to extrude one layer of paste due to water’s high latent heat, thus leaving the extruded paste in its semi-liquid state and causing the part to deform or even collapse. Therefore, …

Active Storage And Ssd Caching In An Object Storage Environment, Michael T. Runde

Master's Theses

The advancing performance and lowering costs required to implement additional processing power on system peripherals such as disk drives are increasingly allowing additional computing ability to be located directly on individual drives. Active Storage attempts to take advantage of this excess by moving some computationally intensive applications directly to the disk drives. This can remove the bottlenecks seen through interconnects between the drives and the CPU of an initiating system as well as remove the need for systems to handle these applications.

The contributions of this thesis are in two areas. The first is the development of a framework designed …

Real-Time Target Following Using An Unmanned Rotorcraft With A Laser Rangefinder, Bryce Sanders Pincock

Theses and Dissertations

Micro-unmanned aerial rotorcraft are quickly gaining acceptance as indoor platforms for performing stealth, surveillance, and rescue and reconnaissance missions. These rotorcraft are generally required to operate in cluttered, unknown, and dynamic GPS-denied environments, which present threats to the safe operation of the vehicle. To overcome these environmental challenges, we describe a system that is capable of localizing itself by producing accurate odometry estimates that can detect and track moving objects and avoid collisions with obstacles while following a moving target using a laser range finder. Our system has been implemented in the Simulink environment in MATLAB. Various simulations have shown …

Understanding Noble Metal Addition In Cobalt Fischer Tropsch Catalysts, Kari Marie Cook

Theses and Dissertations

The effects of noble metal (NM) promotion and deposition order (co-deposition of NM with the final Co deposition [co-dep] or sequential deposition of NM after Co deposition [seq-dep]) on surface area, pore size, metal retention, crystallite size, noble metal distribution and bonding in Co Fischer Tropsch (FT) catalysts were studied as were the resulting Co reducibility and Fischer Tropsch activity/selectivity properties. Catalysts containing nominally 25wt% Co with either 0.3 wt% Ru, 0.58 wt% Pt, 0.55wt% Re, or no NM on a La-stabilized-Al2O3 support were prepared by wet deposition. The Co, Pt, and Re were uniformly dispersed, but Ru distribution and …

Interactions Of An Additive Manufacturing Program With Society, Frank W. Liou, Ming-Chuan Leu, Robert G. Landers

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Additive Manufacturing (AM) has shown considerable promise for the future but also proposes some challenges. Many AM barriers tend to be non-technical and instead are human-centric issues such as lack of education of practitioners in AM capabilities, cultural differences, vested interests, and potentially lack of imagination. It is highly desirable for all research and educational institutions to help address these issues. This paper summarizes the additive manufacturing research and education program at the Missouri University of Science and Technology (Missouri S&T) and its interactions with various constituents, including K-12 students, undergraduate and graduate students, distance students, and industry.

Experimental Study Of Polymer Electrolyte Membrane Fuel Cells Using A Graphite Composite Bipolar Plate Fabricated By Selective Laser Sintering, Nannan Guo, Ming-Chuan Leu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Selective Laser Sintering (SLS) can be used to fabricate graphite composite bipolar plates with complex flow fields for Polymer Electrolyte Membrane (PEM) fuel cells. The additive manufacturing process can significantly reduce the time and cost associated with the research and development of bipolar plates as compared to other fabrication methods such as compression molding. In this study, bipolar plates with three different designs, i.e., parallel in series, interdigitated, and bio-inspired, were fabricated using the SLS process. The performance of these SLS-fabricated bipolar plates was studied experimentally within a fuel cell assembly under various operating conditions. The effect of temperature, relative …

A Study Towards Development Of An Automated Haptic User Interface (Ahui) For Individuals Who Are Blind Or Visually Impaired, Ravi Rastogi

Theses and Dissertations

An increasing amount of information content used in schools, work and everyday living is being presented in graphical form, creating accessibility challenges for individuals who are blind or visually impaired, especially in dynamic environments, such as over the internet. Refreshable haptic displays that can interact with computers can be used to access such information tactually. Main focus of this study was the development of specialized computer applications allowing users to actively compensate for the inherent issues of haptics when exploring visual diagrams as compared to vision, which we hypothesized, would improve the usability of such devices. An intuitive zooming algorithm …

Automation Of Landmark Selection For Rodent Brain Mri-Histology Registration Using Thin-Plate Splines, Ayan Sengupta

School of Computing: Dissertations, Theses, and Student Research

Image registration is the process of aligning two different images of the same object taken at different times, at different orientations or using different instruments. This is common in medical applications since multiple modalities are used to image different parts of the body. This is an important early step in many diagnostic procedures such as change detection, monitoring tumor or quantifying spread of a disease. The widely used landmark based registration approach is tedious, time consuming, inconsistent and error prone. Furthermore, the standard schemes based on rigid and affine transformation can only describe global geometric differences between the objects of …

The Effect Of Friction Stir Welding Process Parameters On Charpy V-Notch Impact Toughness In Hsla-65, Samuel C. Sanderson

Theses and Dissertations

HSLA-65 steel (6.4 mm thick) was friction stir welded at various welding speeds and spindle speeds. Varying weld parameters provided a range of heat inputs. Impact toughness was evaluated as a function of the different weld parameters and corresponding weld heat inputs. Charpy V-Notch (CVN) tests were conducted in parent material and at both the weld nugget centerline and heat-affected zone (HAZ) locations. The upper shelf CVN impact energy of the weld nugget was above that of the base metal for all weld parameters. The upper shelf impact toughness in the HAZ was largely unaffected by changing weld parameters. The …

Using Motion Fields To Estimate Video Utility And Detect Gps Spoofing, Brandon T. Carroll

Theses and Dissertations

This work explores two areas of research. The first is the development of a video utility metric for use in aerial surveillance and reconnaissance tasks. To our knowledge, metrics that compute how useful aerial video is to a human in the context of performing tasks like detection, recognition, or identification (DRI) do not exist. However, the Targeting Task Performance (TTP) metric was previously developed to estimate the usefulness of still images for DRI tasks. We modify and extend the TTP metric to create a similar metric for video, called Video Targeting Task Performance (VTTP). The VTTP metric accounts for various …

Multi-Color Cavity Ringdown Based Detection Method And Apparatus, Scott W. Reeve, Susan Davis Allen

Mechanical Engineering - Daytona Beach

A multi-color cavity ringdown based spectrometer system is housed in a light tight enclosure to detect the presence of trace quantities of gas phase molecules emanating from a subject, explosives, drugs, or hazardous materials. A method is also disclosed for simultaneous real time detection of gas phase molecules emanating from explosives, drugs, hazardous materials, a subject's breath skin or bodily fluid.

Efficient Characterization Of Structural Dynamic Responses Under Uncertainties: From Order-Reduced Simulation To Data-Driven Emulation, Zeping Xia

Master's Theses

The efficiency of sampling remains as one of the major challenges for uncertainty analysis in structural dynamics. In the context of numerical experiments, this difficulty primarily lies in the fact that every single run of a numerical model, which usually is of large scale in modern engineering practice, would be expensive in terms of CPU times and memories. Nonetheless, understanding and predicting dynamic characteristics of structural systems with uncertainties is important for structural design, assessment and control. In order to develop fast and economical sampling techniques for characterizing structural dynamics, we explored two categories of methods from two opposite direction: …

The Extraction Of Shock Waves And Separation And Attachment Lines From Computational Fluid Dynamics Simulations Using Subjective Logic, Matthew C. Lively

Theses and Dissertations

The advancement of computational fluid dynamics to simulate highly complex fluid flow situations have allowed for simulations that require weeks of computation using expensive high performance clusters. These simulations often generate terabytes of data and hinder the design process by greatly increasing the post-processing time. This research discusses a method to extract shock waves and separation and attachment lines as the simulation is calculating and as a post-processing step. Software agents governed by subjective logic were used to make decisions about extracted features in converging and converged data sets. Two different extraction algorithms were incorporated for shock waves and separation …

Lateral Resistance Of Piles Near Vertical Mse Abutment Walls, Jacob S. Price

Theses and Dissertations

Full scale lateral load tests were performed on five piles located at various distances behind MSE walls. Three of the five test piles were production piles used to support bridges, and the other two piles were located behind a MSE wing walls adjacent to the bridge abutment. The objective of the testing was to determine the effect of spacing from the wall on the lateral resistance of the piles and on the force resisted by the MSE reinforcement. Tentative curves have been developed showing p-multiplier vs. normalized spacing behind wall for a length to height ratio of 1.1 and 1.6. …

Piezoelectric Probes And Their Capacity To Monitor Time Varying Viscosity, Eman Ahmed

Theses and Dissertations

Real-time, bedside observation of patient clotting is essential in various surgeries in the operating room (OR), but specifically during cardiac surgeries. The objective of this thesis is to design and test a new piezoelectric device that can be used for viscoelasticity measurement with time as a Point of Care (POC) test. Slow turnaround times (TAT) of current methods to monitor blood viscoelastic changes in patients have led to excessive bleeding and the need for blood transfusions in many situations (Despotis et al, 1997). This study shows that the phase shift produced by a resonator sensor can be related to the …

Size-Dependent Hardness Of Nanoscale Metallic Contacts From Molecular Dynamics Simulations, Hojin Kim, Alejandro Strachan

Birck and NCN Publications

We characterize how size and shape affects the hardness of nanoscale metallic contacts using large-scale molecular dynamics (MD) simulations. High-aspect-ratio contacts continue the experimentally observed trend of hardening with decreasing contact size down to the sub-10-nm regime. However, we find that this effect is shape dependent and the rate of hardening with decreasing contact size diminishes as the aspect ratio of the asperities becomes smaller. Interestingly, low-aspect-ratio asperities that can support simple dislocation glide exhibit softening with decreasing size. A detailed analysis of the MD trajectories reveals the dislocation mechanisms that govern these complex size effects.

A Digital X-Ray Tomosynthesis Coupled Near Infrared Spectral Tomography System For Dual-Modality Breast Imaging, Venkataramanan Krishnaswamy, Kelly E. Michaelsen, Brian W. Pogue, Steven P. Poplack, Ian Shaw, Ken Defrietas, Ken Brooks, Keith D. Paulsen

Dartmouth Scholarship

A Near Infrared Spectral Tomography (NIRST) system has been developed and integrated into a commercial Digital Breast Tomosynthesis (DBT) scanner to allow structural and functional imaging of breast in vivo. The NIRST instrument uses an 8-wavelength continuous wave (CW) laser-based scanning source assembly and a 75-element silicon photodiode solid-state detector panel to produce dense spectral and spatial projection data from which spectrally constrained 3D tomographic images of tissue chromophores are produced. Integration of the optical imaging system into the DBT scanner allows direct co-registration of the optical and DBT images, while also facilitating the synergistic use of x-ray contrast as …

Study On The Fracture Toughness Of Friction Stir Welded Api X80, Allan M. Tribe

Theses and Dissertations

High strength low alloy (HSLA) steels have been developed to simultaneously have high yield strength and high fracture toughness. However, in practical applications steel must be welded. Traditional arc welding has proven detrimental to the fracture toughness of HSLA steels. Friction stir welding has recently shown mixed results in welding HSLA steels. The range of welding parameters used in these recent studies however has been very limited. With only a few welding parameters tested, the effect of spindle speed, travel speed, and heat input on the fracture toughness of friction stir welded HSLA steel remains unknown. To understand how the …

Integrated Fiber Electrospinning: Creating Spatially Complex Electrospun Scaffolds With Minimal Delamination, Casey Grey

Theses and Dissertations

Tissue engineering scaffolds come in many shapes and sizes, however, due to difficulty manufacturing the microstructure architecture required in tissue engineering, most scaffolds are architecturally non-dynamic in nature. Because the microstructural architecture of all biological tissues is inherently complicated, non-dynamic tissue engineering scaffolds tend to be a poor platform for tissue regeneration. The current method for manufacturing dynamic tissue engineering scaffolds involves electrospinning successive layers of different fibers, an approach that exhibits no fiber transition between layers and subsequent delamination problems. In this study we aim to address the design challenges of tissue engineering scaffolds through our novel integrated fiber …

Empirical Model For The Transconductance-Current Dependence Of Short-Channel Mosfets, Vladimir I. Prodanov

Electrical Engineering

This work is concerned with the g_m-I dependence of sub-micrometer MOSFETs. The transconductance-current expression given by the Advanced Compact Model (ACM) is reviewed and simple modification is proposed. The modification yields an expression which (with proper parametrization) captures the g_m-I dependence of short-channel MOSFETs. The proposed expression is “universal” in the sense that it is capable of modeling the g_m-I dependence of long-channel MOSFETs, short-channel MOSFETs, and resistively-degenerated BJTs.

Design Of Wideband Continuous-Time Δς Adcs Using Two-Step Quantizers, Sakkarapani Balagopal, Vishal Saxena

Electrical and Computer Engineering Faculty Publications and Presentations

Continuous-time delta sigma (CT-ΔΣ) ADCs are established as the data conversion architecture of choice for the next-generation wireless applications. Several efforts have been made to simultaneously improve the bandwidth and dynamic range of ΔΣ ADCs. We proposed using two-step quantizer in a single-loop CT-ΔΣ modulator to achieve higher conversion bandwidth. This paper presents a tutorial for employing the design technique through a 130n CMOS implementation. The proposed 640 MS/s, 4^th order continuous-time delta sigma modulator (CT-ΔΣM) incorporates a two-step 5-bit quantizer, consisting of only 13 comparators. The CT-ΔΣM achieves a dynamic range of 70 dB, peak SNDR of 65.3 …

A 1 Gs/S, 31 Mhz Bw, 76.3 Db Dynamic Range, 34 Mw Ct-Δς Adc With 1.5 Cycle Quantizer Delay And Improved Stf, Sakkarapani Balagopal, Vishal Saxena

Electrical and Computer Engineering Faculty Publications and Presentations

A 1 GS/s Continuous-time Delta-Sigma modulator (CT-ΔΣM) with 31 MHz bandwidth, 76.3 dB dynamic range and 72.5 dB signal-to-noise is reported in a 0.13μm CMOS technology. The design employs an excess loop delay (ELD) of more than one clock cycle for achieving higher sampling rate. The ELD is compensated using a fast-loop formed around the last integrator by using a sample-and-hold. Further, the effect of this ELD compensation scheme on the signal transfer function (STF) of a feedforward CT-ΔΣ architecture has been analyzed and reported. In this work, an improved STF is achieved by using a combination of feed-forward, feed-back …

Impact Of Salt On Denitrification Potential In Roadside Environments, Nakita A. Lancaster

Master's Theses

Urban systems are impacted by changes in hydrology and water chemistry, altering their ability to mitigate detrimental impacts to coastal water bodies, particularly those that result from high volumes of stormwater runoff. The elevated level of impervious cover increases not only runoff but also contaminant loading of nutrients, metals, and road salt used for deicing in cold weather climates. Current stormwater management strategies, while focused on managing the changes in hydrology associated with urbanization, also are designed to mitigate the pollutant loading. Here we investigate the impact that road salt will have on nitrogen removal in roadside environments. Sediments were …

Creek And Lake Water Analysis Of The Little Calumet East Branch Watershed, Nicholas H. Feller, Melissa Dorton

Symposium on Research and Creative Expression (SORCE)

The overall goal of this project is to collect and analyze baseline water quality data in the Little Calumet East Branch (LCEB) watershed. This watershed spans portions of Porter and LaPorte counties in northwest Indiana and drains into Lake Michigan. The LCEB currently has impaired water quality. The Indiana Department of Environmental Management (IDEM) has awarded Save the Dunes Conservancy Foundation a two year grant to develop and implement a Watershed Management Plan to improve water quality. During the summer of 2012, the following water quality parameters were collected weekly from 15 sites spread throughout the watershed: 1) pH, 2) …

The Design And Manufacturing Of The Solar Furnace Reactor Table, Chris Baum, Zach Saylor, Andrew Schiller

Symposium on Research and Creative Expression (SORCE)

The James S. Markiewicz Solar Energy Research Facility at Valparaiso University will concentrate energy from the sun into a reactor containing unprocessed materials. The concentrated light causes a reaction to occur, turning unprocessed materials into alternative energy products. Accurate placement of the reactor at the focal point of the concentrator is necessary to allow the maximum amount of solar energy to enter the reactor. The Reactor Table was designed and built by Valparaiso University students and faculty. The table controls the placement of the reactor at the focal point of the concentrator quickly and easily by using a computer located …

Designing A Calorimeter To Calibrate An Optical Radiative Flux Measurement System To Find The Power Entering A Solar Reactor, Jesse Fosheim, Melissa Meyer, Jonathan Ogland-Hand

Symposium on Research and Creative Expression (SORCE)

A solar furnace has been constructed at Valparaiso University to test the performance of various solar chemical reactors. A primary performance index of a solar chemical reactor is the efficiency, or the fraction of the energy that enters the reactor that is utilized in the chemical reaction. To calculate this efficiency, we must first know how much solar power is entering the reactor. An optical radiative flux measurement system has been developed that gives the solar flux distribution over the aperture of the reactor, but must be calibrated to provide the actual power level. Therefore, a calorimeter was designed and …

Electrical Control And Safety System For Solar Furnace, Parisa Nasserifar, Jason Toberman

Symposium on Research and Creative Expression (SORCE)

The Valparaiso University College of Engineering has recently received a donor gift and a federal earmark to design and manufacture a solar furnace facility. In the solar facility, a heliostat will reflect sunlight straight into the concentrator at every instant. However, due to manufacturing tolerances and inaccuracy in sun’s position model a sun sensor is added in the heliostat sun tracking system. The sun sensor fine adjusts the heliostat’s position so the reflected sunlight is normal to the concentrator. Our goal is to develop a sun sensor that provides an unbalanced output signal when the sensors receive an unbalanced light …

Vu Solar Furnace: Final Design And Construction Of Louver System, Chris Baum, Zach Saylor, Andrew Schiller, Gretchen Vanheeren

Symposium on Research and Creative Expression (SORCE)

Solar energy is an environmentally clean and abundant alternative to the use of fossil fuels. One method of harnessing solar energy, solar thermal electrochemistry, uses a solar furnace to concentrate sunlight and heat a reactor to temperatures around 2000 K. At such high temperatures, metallic oxides can be decomposed into metals and oxygen with minimal electrical work. The solar furnace used for this process consists of a heliostat, which tracks the sun; a concentrator, which focuses the light to a single point; and a reactor in which the chemical reaction takes place. To control the amount of sunlight entering the …